code: def testTwoSequences(self):
      sequence0 = [7, 12, 16]
      sequence1 = [3, 4, 5]
  
      identity = lambda x: int(x)
      times3 = lambda x: int(3 * x)
  
      expectedValues = [
          (7, [7], None),
          (9, None, [3]),
          (12, [12], [4]),
          (15, None, [5]),
          (16, [16], None),
      ]
  
      i = 0
      for data in groupby2(sequence0, identity, sequence1, times3):
          self.assertEqual(data[0], expectedValues[i][0])
          for j in xrange(1, len(data)):
              temp = list(data[j]) if data[j] else data[j]
              self.assertEqual(temp, expectedValues[i][j])
          i += 1
  
file_path: nupic-legacy/tests/unit/nupic/support/group_by_test.py
imports: import unittest
  from nupic.support.group_by import groupby2
label_desc: Use image node_id 2 for calling the GroupByTest obj's underlying member method code with example usage: obj.testTwoSequences() without return types